COMPARATIVE STUDY REGARDING THE MICRO-HARDNESS OF SOME AESTHETIC RESTORATIVE MATERIALS

Abstract

Background In recent years and mainly after 2000, the trends in terms of the structure of dental composites have addressed the progressive decrease of filler particle size down to nanometric level. All these result from the need to continuously improve the properties of the composite material such as their hardness, mechanical resilience, contraction to polymerization and polymerization stress. The present study aimed to test the microhardness and to determine its variation in case of some coronary esthetic restorative materials commonly used in dental practice. Material and methods Experimental researches concerning the determination of the microhardness variations were performed on four direct dental restorative light-curing composite (Herculite XRV Ultra, Synergy D6 and Brilliant - nanohybrid composite and Latelux -microhybrid composite). Specimens, with a diameter of 10 × 10 mm and 4 mm thick, were developed in the Dental Materials laboratory of the Dental Medicine Faculty of "Gr. T. Popa " University of Medicine and Pharmacy of Iasi, in accordance with the manufacturer indications. Micro-hardness testing was performed in the Department of Material Engineering and Industrial Security of the Faculty of Materials Science and Engineering from “Gheorghe Asachi” Techncial University of Iaşi. Results Tests have revealed that direct composite resin Brilliant from Coltene Whaledent presents the highest values of Vickers micro-hardness. Conclusions For the selection and use of direct composite resins dentist must take into account the composition, clinical performance, handling characteristics and their biomechanical behavior, an important parameter being the micro-hardness